Ventilation question

I found this site by Googling DIY HVAC. I want to replace a vent that is in the basement. It is old and actually leaks. Seems like an easy DIY job that would make my day when completed.

So being the wise person, I am researching HVAC. The house I live in was built in 1927, but I don't know right now when the heating and ventillation system was put in. How big a project is it to replace a duct leading to a vent? It looks like an easy, almost fun, thing to do but then I found this forum and would love to hear some opinions on the complexity.

The vent I want to replace leads from a 2-year-old Goodman furnace. It is approximately 3 feet in length and ends
in the bathroom above. Thanks for being here and any replies.

Is this a supply or return duct? Not that it really matters...a direct replacement should be straight forward. That doesn't mean that it is the right thing to do, though.

Balancing a forced air system is a science that, when done right, keeps all rooms the proper temp. Done wrong, and you can either end up sucking in outside air or blowing air out, cold rooms, or excessively hot ones.

Jim, I started replacing the heat registers, the things that go over the holes where the heat comes out. The sheet metal is very old and needs to be replaced, if not for function, then for cleanliness. The vents from the furnace, which is in the basement, are pretty old. They're not shiny by any means. I want to replace them and not change the placement or anything like that. It's a Goodman furnace. I also have an Aprilaire unit that hasn't worked for decades.

Contemplating getting a new Aprilaire and new ductwork. Ductwork looks like a project that I could do. I would just replace what is there now.

Replacing a circa 1927 duct system in-toto should be done to a complete ACCA Manual-D level or you're just wasting your time and money. If you're not going to fix the duct design, the new shiny ducts won't work any more efficiently or effectively than the dull-gray ones.

If you're concerned about the 85 years of dust and crud buildup in the ducts, don't be, it's usually pretty inert/benign, and what's there isn't going anywhere if it hasn't been blown out by the air handler. Or hire one of those duct-cleaning outfits to vacuum them out and use decent filters thereafter. It HAS to be a lot cheaper to clean them than replace them.

Ducts don't need to be shiny to work, but they DO need to be sealed. A better use of DIY time than duct replacement would be to seal every seam and joint with duct-mastic, and seal the ducts to the wall/floor/ceiling at every register to avoid pulling/blowing air into joist or stud cavities.